Buggy code:
class Coders { static InputStream addDecoder ( final InputStream is , final Coder coder , final byte [ ] password ) throws IOException { } static OutputStream addEncoder ( final OutputStream out , final SevenZMethod method , final byte [ ] password ) throws IOException { } static Coders . CoderId [ ] coderTable = new Coders . CoderId [ ] { new Coders . CoderId ( SevenZMethod . COPY , new Coders . CopyDecoder ( ) ) , new Coders . CoderId ( SevenZMethod . LZMA , new Coders . LZMADecoder ( ) ) , new Coders . CoderId ( SevenZMethod . LZMA2 , new LZMA2Decoder ( ) ) , new Coders . CoderId ( SevenZMethod . DEFLATE , new Coders . DeflateDecoder ( ) ) , new Coders . CoderId ( SevenZMethod . BZIP2 , new Coders . BZIP2Decoder ( ) ) , new Coders . CoderId ( SevenZMethod . AES256SHA256 , new Coders . AES256SHA256Decoder ( ) ) } ; static class CoderId { CoderId ( SevenZMethod method , final Coders . CoderBase coder ) { } final SevenZMethod method ; final Coders . CoderBase coder ; } abstract static class CoderBase { abstract InputStream decode ( final InputStream in , final Coder coder , byte [ ] password ) throws IOException ; OutputStream encode ( final OutputStream out , final byte [ ] password ) throws IOException { } } static class CopyDecoder extends Coders . CoderBase { @ Override InputStream decode ( final InputStream in , final Coder coder , byte [ ] password ) throws IOException { return in ; } @ Override OutputStream encode ( final OutputStream out , final byte [ ] password ) { } } static class LZMADecoder extends Coders . CoderBase { @ Override InputStream decode ( final InputStream in , final Coder coder , byte [ ] password ) throws IOException { byte propsByte = coder . properties [ 0 ] ; long dictSize = coder . properties [ 1 ] ; for ( int i = 1 ; i < 4 ; i ++ ) { <START_BUG> dictSize |= ( coder . properties [ ( i + 1 ) ] ) << ( 8 * i ) ; <END_BUG> } if ( dictSize > ( LZMAInputStream . DICT_SIZE_MAX ) ) { throw new IOException ( "Dictionary<seq2seq4repair_space>larger<seq2seq4repair_space>than<seq2seq4repair_space>4GiB<seq2seq4repair_space>maximum<seq2seq4repair_space>size" ) ; } return new LZMAInputStream ( in , ( - 1 ) , propsByte , ( ( int ) ( dictSize ) ) ) ; } } static class DeflateDecoder extends Coders . CoderBase { @ Override InputStream decode ( final InputStream in , final Coder coder , final byte [ ] password ) throws IOException { return new InflaterInputStream ( new Coders . DummyByteAddingInputStream ( in ) , new Inflater ( true ) ) ; } @ Override OutputStream encode ( final OutputStream out , final byte [ ] password ) { } } static class BZIP2Decoder extends Coders . CoderBase { @ Override InputStream decode ( final InputStream in , final Coder coder , final byte [ ] password ) throws IOException { return new BZip2CompressorInputStream ( in ) ; } @ Override OutputStream encode ( final OutputStream out , final byte [ ] password ) throws IOException { } } static class AES256SHA256Decoder extends Coders . CoderBase { @ Override InputStream decode ( final InputStream in , final Coder coder , final byte [ ] passwordBytes ) throws IOException { return new InputStream ( ) { private boolean isInitialized = false ; private CipherInputStream cipherInputStream = null ; private CipherInputStream init ( ) throws IOException { if ( isInitialized ) { return cipherInputStream ; } final int byte0 = 255 & ( coder . properties [ 0 ] ) ; final int numCyclesPower = byte0 & 63 ; final int byte1 = 255 & ( coder . properties [ 1 ] ) ; final int ivSize = ( ( byte0 > > 6 ) & 1 ) + ( byte1 & 15 ) ; final int saltSize = ( ( byte0 > > 7 ) & 1 ) + ( byte1 > > 4 ) ; if ( ( ( 2 + saltSize ) + ivSize ) > ( coder . properties . length ) ) { throw new IOException ( "Salt<seq2seq4repair_space>size<seq2seq4repair_space>+<seq2seq4repair_space>IV<seq2seq4repair_space>size<seq2seq4repair_space>too<seq2seq4repair_space>long" ) ; } final byte [ ] salt = new byte [ saltSize ] ; System . arraycopy ( coder . properties , 2 , salt , 0 , saltSize ) ; final byte [ ] iv = new byte [ 16 ] ; System . arraycopy ( coder . properties , ( 2 + saltSize ) , iv , 0 , ivSize ) ; if ( passwordBytes == null ) { throw new IOException ( "Cannot<seq2seq4repair_space>read<seq2seq4repair_space>encrypted<seq2seq4repair_space>files<seq2seq4repair_space>without<seq2seq4repair_space>a<seq2seq4repair_space>password" ) ; } final byte [ ] aesKeyBytes ; if ( numCyclesPower == 63 ) { aesKeyBytes = new byte [ 32 ] ; System . arraycopy ( salt , 0 , aesKeyBytes , 0 , saltSize ) ; System . arraycopy ( passwordBytes , 0 , aesKeyBytes , saltSize , Math . min ( passwordBytes . length , ( ( aesKeyBytes . length ) - saltSize ) ) ) ; } else { final MessageDigest digest ; try { digest = MessageDigest . getInstance ( "SHA-256" ) ; } catch ( NoSuchAlgorithmException noSuchAlgorithmException ) { IOException ioe = new IOException ( "SHA-256<seq2seq4repair_space>is<seq2seq4repair_space>unsupported<seq2seq4repair_space>by<seq2seq4repair_space>your<seq2seq4repair_space>Java<seq2seq4repair_space>implementation" ) ; ioe . initCause ( noSuchAlgorithmException ) ; throw ioe ; } final byte [ ] extra = new byte [ 8 ] ; for ( long j = 0 ; j < ( 1L << numCyclesPower ) ; j ++ ) { digest . update ( salt ) ; digest . update ( passwordBytes ) ; digest . update ( extra ) ; for ( int k = 0 ; k < ( extra . length ) ; k ++ ) { ++ ( extra [ k ] ) ;

Fix:
dictSize |= ( ( coder . properties [ ( i + 1 ) ] ) & 255L ) << ( 8 * i ) ;